Container sealing method and apparatus



June 29, 1965 NELSON ETAL 3,191,352

CONTAINER SEALING METHOD AND APPARATUS Filed Sept. 18. 1962 4 Sheets-Sheet 1 INVEN TORS DAVID G. NELSON FRANK M. KELLY iwasw ATTORNEY J 1965 D. G. NELSON ETAL 3, ,3

CONTAINER SEALING METHOD AND APPARATUS Filed Sept. 18. 1962 4 Sheds-Sheet 2 INVENTORS DAVID G. NELSON FRANK M. KELLY June 29, 1965 D. G. NELSON ETAL ,3

CONTAINER SEALING METHOD AND APPARATUS Filed Sept. 18. 1962 4 sheds-sheet s IN VEN TORS DAVID G. NELSON BY FRANK M. KELLY ATTORNEY June 29, 1965 D, G. NELSON ETAL CONTAINER SEALING METHOD AND APPARATUS 4 Sheets-Sheet 4 Filed Sept. 18. 1962 INVENTORS DAVID G. NELSON FRANK M. KELLY ATTORNEY United States Patent 3,191,352 CONTAINER SEALING METHOD AND APPARATUS David G. Nelson and Frank M. Kelly, Richmond, Ind.,

assignors to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 18, 1962, Ser. No. 224,456 11 Claims. (Cl. 5322) This invention relates tothe art of hermetically sealing containers with closures or caps, hereafter simply called caps and it particularly concerns hot vapor vacuumizing and cap sealing screw threaded containers, such as jars, cans, bottles and similar packaging receptacles, to produce vacuum-sealed packages. 7 V

Herein, the term threaded container refers to a container formed with an external screw thread neck finish. It is also to be understood that the term cap includes a customary sealing liner or gasket.

In the commercial packaging of foodstuffs for the retail trade in the well-known threaded containers, a particularly eiiective and desired cap seal therefor has been provided by the well-known method of progressively spinning or rolling the cap skirt into conformity with the container neck finish while the cap is held in sealing engagement with the top or mouth rim of the container. It also has been customary to effect thi cap seal after introducing hot condensable vapor or steam into the mouth or head space of the container and causing such vapor to cool or condense while it is confined within the container by the cap so as to produce a partial vacuum in the container, this being referred to in the industry as vacuumizing and vacuum-sealing. Heretofore, this hot vaper vacuumizing and roll-on cap sealing of the containers in commercial practice at least has been a two-station seal ing operation. This has been a disadvantage in sealing practice, inasmuch as resort to artificial cooling of the containers, steamed and loosely capped in the first stage,

cooling, but has permitted internal pressure variation and vacuum impairment, particularly in attempting to satisfy the rapid commercial packaging rates required for high volume production which is in excess of 600 sealed packages per minute, as in the case of baby foods, for example.

It is an object of this invention to provide a simplified method and mechanism which will overcome the disadvantages hereabove pointed out, dispense with artificial cooling and which will hot vapor vacuumize and completely aflix caps on threaded containers at a single sealing station and at rapid production rates compatible with commercial packaging line rates and with a consistently uniform degree of high vacuum in the sealed packages. 7

Another object of the invention is the provision of a method and apparatus by which a plain-skirt cap resting loosely upon a threaded container will be lifted solely by hot vapor jets and vapor admitted under the cap and into the container head space to displace the air normally present and then, while the vapor jets are still acting, the cap will be sealingly disposed on the container and affixed thereto by rolling the cap skirt into conformity with the container neck finish, to result in a vacuum-sealed package when the trapped vap or therein cools.

A further object'of the invention is to provide an automatic, rotary threaded container sealing machine embodying a multiplicity of sealing heads, each provided "ice with a cap-lifting. vapor or gas jet ring cooperable with a cap-sealing pressure plate member and cap skirt threadrolling members for vapor vacuumizing and cap afiixing each container presented thereto, and in which the jet ring and thread-rolling members are non-rotatable, while the pressure plate member and a container rest pad associated with the head are positively rapidly rotated for rotating the container and its cap with respect to the thread-rolling members, but so constructing and mounting the rest pad as to prevent container rotation until top sealing pressure is applied to the container and its cap, whereby centrifugal spilling of the container contents is prevented.

These and additional objects and advantages of the invention will be better understood, or apparent to those skilled in the art, when considered in the light of the detailed description which follows; taken in conjunction with the accompanying drawings illustrating a preferred embodiment of apparatus incorporating the invention, and in which:

FIG. 1 is a plan view of a sealing machine of the automatic type which embodies the invention, and also serves as a timing diagram;

FIG. 2 is a side elevational view of the sealing machine;

FIG. 3 is a fragmentary cross-sectional view, on an enlarged scale, taken on the line IIIIII of FIG. 1 and illustrating the internal construction of the sealing turret mechanism;

FIG. 4 is a vertical cross-sectional view, on an enlarged scale, of a sealing head assembly and associated operating mechanism and illustrating the head unit in its lowered steaming position in relation to the top portion of a threaded container as is effected during the container sealing cycle;

FIG. 5 is a fragmentary cross-sectional view of the lower portion of the sealing head unit of FIG. 4 illustrating it after it has reached that point in the sealing cycle where the cap has been seated on the container and the thread rolling operation on the cap skirt has been completed;

FIG. 6 is a fragmentary plan-section view taken on the line VIVI of FIG. 4 showing the slidable mounting of the upper part of the sealing heads, and

FIG. 7 is a similar view taken on the line VIIVII of FIG. 4 showing the mounting of the lower part of the sealing heads.

Referring to FIGS. 1 and 2, the machine comprises an elevated base 1 supported by leg brackets 2 having screws 3 so that leveling the machine with the base at a desired elevation above the floor line may be readily accomplished. The base is provided with a line conveyor 4 which is mounted on pulleys at the respective ends of side extensions 5 attached to the base 1, thus enabling the machine to be installed in a high-speed production line to receive product-filled containers 6 as they come from a filler machine. The filled containers are received on the left hand end of conveyor 4 and a spacer screw 7 which is operatively coupled to the machine drive spaces the containers so that a container 6 is placed in each pocket 8 of a horizontal intake star wheel 9, as illustrated in FIG. 1. The star wheel 9 feeds the containers into a rotary sealing mechanism 10 which is rotatable about a vertical axis and during travel of the containers about such axis, they are completely sealed, as hereinafter described, and are removed from the sealing mechanism by a take-out star wheel 11 which serves to replace them on the line conveyor 4 for discharge from the machine.

The rotary sealing mechanism, best shown in FIG. 3, comprises a vertical stationary post or column 12 which is supported by a hubbed plate member 13 bolted. to the underside of the base 1, this plate member including a shell cap 14 bolted thereto which carries a thrust bearing 15 on which a worm wheel 16 bears and helps to support the post 12. The post 12 is vertically adjustable in relation to the base 1 by rotation of the worm Wheel 16 which is internally threaded and engages threads on the lower end of the post, rotation of the worm wheel being effected, as desired, by a meshing Worm 17 and a hand Wheel 18. The purpose of this arrangement is to permit the machine to be adjusted to seal containers of different height ranges.

The base 1 is preferably recessed at its upper side and carries a top or cover plate 19, thereby, forming a closed gear case for drive gears 20, 21 and 22 disposed therein (FIG. 2). Above the cover plate is a rotatable table 23 having a wear plate 23a inset in the top of the rim area thereof, and having upper and lower hubs carrying hearing sleeves which rotatably support the table on the post 12, the table being additionally supported by hearing 24 between its lower hub and plate member 13 and at the underside of its rimby a rim bearing 25 carried by cover plate 19. Gear 21) 'is bolted to the lower hub of table 25 and is in mesh with the take-out star wheel 11 drive gear 22 and with the intake star wheel 9 drive gear 21, the latter being driven by a pinion gear 26 which is driven by a gear motor unit 27 through a speed reducer 28 (FIG. 2). Thus, the two star wheels 9 and 11 and the rotary sealing mechanism are driven in exact synchronism so that the feeding of the containers into and out of the sealing mechanism is synchronized with the rotary movement of the individual sealing heads 29 of the sealing mechanism. Conveyor 4 and screw 7 are also coupled to the drive motor 27 by being coupled to the intake star wheel drive gear 21 by suitable gear and shaft systems indicated generally at 313 and 31, respectively, in FIGS. 1 and 2, and are thus synchronized with the star wheels.

Intake star wheel 9 is rotatable about a stationary vertical post 32 (FIG. 2) which may be mounted like the post 12 in base 1. At the point of alignment of its successive pockets 8 with the screw 7 is a bracket supported overhead closure cap denesting and feeding device 34, driven through shaft 33 from the intake star wheel drive gear 21, for the purpose of removing individual slightly tapered, plain-skirt caps from a nested stack and placing a cap 35 on each container as it moves under the cap feeder, so that each container delivered to the rotary sealing mechanism will have its cap loosely resting thereon. Preferably, well-known aluminum caps are used, but caps of other metal may be employed. Suitable cap feeders are commercially available. The preferred feeder here illustrated is disclosed in United States Patent No. 3,018,- 593, which is owned by the assignee of the present invention. By vertical adjustment on its supporting bracket, the cap feeder is properly positioned in relation to the top of the containers. t

The rotary table 23 is provided with a multiplicity of circular container support pads 36 which are rotatably mounted in cavities formed in the table at equiangular intervals in a circle around the table and equal in number to the number of pockets in the star wheel 9. The bottom wall of the cavity is formed with an upstanding annular lip 37 which a rim flange on the'underside of the pad overhangs and a drain bore leads from the cavity wardly extending stub shaft 39 mounted in bearing 40 in the table. The shaft is provided with a central bore extending approximately half its length from the upper end, in which bore is slidably supported a bearing plunger 41 and a backingspring therefor which biases it upwardly. The top of this plunger has bearing engagement with biasing spring pressure normally yieldingly holds the pad out of contact with the head flange 38 and in frictional contact with the plate 23a, so that the pad is normally stationary but can be depressed into frictional driving contact with the head flange 38.

Fixed to the lower end of shaft 39 is a small gear 42 which meshes with a planet gear 43 rotatably secured to the underside of the table and meshes with a large sun gear 44 secured to the cover plate 19 coaxially of the table 23. By this gear arrangement, each shaft 39 is continuously rapidly rotated as the table revolves about the sun gear. However, each pad 36 and a container seated thereon will not rotate until top pressure is applied to the container and its cap during the container sealing cycle, so that centrifugal spilling of the container contents in the early stages of the sealing cycle is prevented. Also mounted on the upper side of the table and rotatable therewith is a star wheel 45 having container receiving pockets co-incident with the support pads 36 into which pockets the containers are successively fed by the intake star wheel 9 at the aligned intake position A between these two star wheels.

Rotatably supported on the post 12 by a thrust bearing 46 in vertically spaced relation to the table 23 is a turret 47 having a downwardly extending hub portion which is unitarily and slidably connected by vertical keys &8 to the upper hub of the table 23 so that the table and the turret are axially movable in relation to each other,

but rotate together about the post '12.- Also rotatably supported on the upper end of the post by bearings 49 is a top plate 59 on which is mounted a manifold 51 having a single fluid supply inlet 52 of the rotary type for admittance of vapor or gas from a supply pipe 53. Flexible conduits 5 lconnect the manifold with each of the sealing heads 29 which are slidably mounted on the turret in the manner now to be described.

Fixed to the post 12 intermediate top plate 50 and the turret 47 are upper and lower plate members 55 and 56 which are interconnected in spaced apart relation by spacer lugs 57 and connecting bolts 58. The upper plate member 55 carries a drum cam 59 having a cam groove 61), While the lower plate member 56 carries a fixed sun gear 61, :a duplicate of the lower sun gear 4 4. Intermediate these parts is a ring member 62 forming an upper part of the turret and. provided with outwardly and up war-dly extending-block portions 63 arranged at equiangular intervals around the ring member and disposed outwardly of the drum cam -59 and the sun gear 61. The vertical sides of the block portions 63 are outwardly convergent, as best seen in FIG. 6, and between adjacent pairs form slideways in each of which the upper body part or case 64 of a sealing head 29 is vertically slidably supported in axial alignment with a container support pad 36 therebelow. The case 64 is of generally keystone shape with V-sides and is retained in the slideway by means of vertical keeper bars 65 secured to the turret 47 which, as shown in FIG. 7, is peripherally V-notched or recessed to provide similar slideways for receiving the lower V-sided block member 66 of the sealing heads for retention by the keeper bars. The top plate 50 is formed with a down turned rim or flange 67 which is bolted to the block portions 63 of the ring member 62 and thus the top plate is rotated from th turret 4 7. In essence, the turret 47, ring member 62 and its integral block portions 63 and the top plate 50, interconnected by the keeper'bars, form .a squirrel cage-like turret structure for slidably supporting the sealing heads for bodily movement about the fixed drum cam 59, sun gear 611and post 12. An advantage of this construction is that a large number of sealing heads 29, twenty-five being here illustrated, is accommodated in a small circle such that the spacing'between containers is reduced to less than their diameter, the rpm. of the table and intake star is kept low without sacrifice of high unit per minute sealed container production rate, thereby reducing centrifugal force on the container contents and eliminating spillage of such contents in high-level till containers, particularly in the case of Wide-mouth type of containers.

The upper case 64 of each sealing head 29 is provided with a cam roller 68 engaged in the groove 60 of drum cam 59, whereby the cam controls the vertical position of the sealing head with respect to the container 6' resting on the pad 36 therebelow. Secured to the bottom of case 64 is a downwardly extending cut-away gear housing 69 provided at its lower end with thread roller operating cam members 70. The upper end of a vertical spindle 71 is supported by thrust and radial bearings mounted in a bearing block 72 which is vertically slidable, but nonrotatable in the axial bore in case 64, and which is yieldingly held against an abutment ring 73 by a heavy compression spring 74 confined between .a thrust plate at the top of the bearing block and a screw plug threaded into the upper portion of the case 64. Within the housing 69, a wide face gear 75 is secured to the spindle and is in mesh with a pinion 76 rotatably secured to the underside of ring member 62 and in mesh with j the sun gear 61. Thereby, the spindle 71 is constantly rotated at the same speed as the stub shaft 39 under the support pad 36, as the sealing heads revolve about the post 12, and the elongated or Wide gear 75 allows vertical movement of the spindle without breaking its drive.

The lower block member 66 of the sealing head 29 is supported on the lower portion of the spindle 71 by bearings 77 so as to move vertically with the spindle, but is held against rotation about the spindle axis by its slidable mounting in the turret. The spindle extends through the block member 66 and carries at its lower end a pressure block 7 8 which is adjustable on the spindle and solidly held normal to the spindle by a backing nut 79. Sw-ivelly secured to the pressure block 78 is a cap engaging pressure plate 80 conform-ed in its lower face to the cap top contour to receive the top of the cap, the swivel mounting between the parts 78 and 80 causing the spindle and hence the sealing pressure to be distributed quite uniformly around the cap, its sealing gasket and the mouth rim of the container to develop an hermetic seal despite slight surface irregularities and variations normally present.

A centrally bored valve body block 81 is secured to the block member 66 and is counterbored in its lower face and receives the upstanding flange of a bottom plate to form a vertically narrow annular vapor ejector or jet ring 8 2 coaxially of-the spindle axis and with an annular distributor passage around the plate flange. This jet ring formation is adapted to encircle the upper portion of a container and itscap. Two series of small bore openings or ports 83 are formed in the flange of the jet ring, one

series above the other and inclined inwardly and upwardly at different angles, so as to direct high velocity steam jets towards the pressure plate 80. The vertical spacing of the jet ring below the bottom of the pressure plate 80 is approximately equal to the depth of the plain skirt of the cap 35. Thus, when the sealing head is lowered to its intermediate container neck embracing or steaming position, as indicated in FIG. 4, the jet ring will be slightly below the top of the container with the lower edge of the cap about even with the lower series of ports 83, to insure cap lifting and vapor injection under the lifted cap.

To control the steam flow to the jets, a control valve is provided, preferably in the form of a sleeve valve tube 84 slidably fitted in a lateral extension of block 81 from which a passage :85 extends radially to the annular passage around the jet ring, the lower end of the valve tube cooperating with a sealing pad 86 against which it is normally held by a spring 87. The upper end of the valve tube is connected to the flexible conduit 54 and the inturned arm of an actuator plate 88, slid-ably mounted on the block 81, is operatively engaged in an upper groove in the valve to unseat it from the sealing pad. The spring 87 acts through the plate 88 to bias the latter and the valve tube downwardly and thus close the valve. A roller 89 carried by actuator plate 88 is adapted to cooperate with a valve actuating cam 90 which extends around a part of the periphery of the rotary sealing mechanism, as shown in FIG. 1.

Carried by the block member 66 of eachsealing head are three thread rolling discs 91 of conventional construction which are rotatably and slidably mounted on levers 92. Each disc is biased upwardly to the position shown in FIG. 4 by a spring 93 which permits it to follow downwardly the screw finish of the container during the cap thread forming operation. The side of the valve body block 81 is appropriately cut out to receive the threading discs and their upright supporting levers. Each lever 92 is connected by a fulcrum pin 94 and a disc pressure control spring 95 to a lever 96 which is pivoted to the lower block 66 at 97. The lever 96 carries at its upper end a roller 98 in engagement with an actuating cam 76 and is biased against such cam by a spring 99.

The illustrated guide rails, which need not be described in detail because they are conventional, are associated with the principal container moving elements of the machine; namely, the screw 7, the line conveyor 4 and each of the rotating star wheels 9, 11 and 45, to cooperate with such elements to keep the containers properly in line during their travel through the machine.

In the operation of the machine which has been described in detail above, the filled threaded containers, automatically or manually delivered to the entry end of conveyor 4 and advanced thereby, are spaced by the screw 7 for pick-up by each pocket of the star wheel 9 and delivered, one-by-one, onto successive support pads 36 of the rotating table 23 and underneath the individual sealing heads 29 at the intake position A (FIG. 1). At this point, the support pad 36 is in its upper position and is not rotating, and the container is merely seated thereon. As each threaded container passes under the cap feeder 34, it receives a plain skirt cap loosely thereon. At the intake position A, the sealing head is in its uppermost position by reason of its cam roller 68 being in the high part of the drum cam groove 60, so there is ample space beneath the sealing head to receive the container and its cap. As the movement of the table carries the container between points A and B, the latter selected to be ahead of or at the start end of cam 90, the drum cam 59 moves the entire sealing head 29 down to its intermediate position shown in FIG. 4. In this position, the vapor ejector ring 82 embraces the neck finish of the container and the pressure plate is above the cap a distance somewhat less than the cap skirt depth,

so as to limit subsequent cap lifting by projected vapor.

After the sealing head is thus lowered, the valve actuator roller 89 meets the cam and starts to open valve 84 which is fully open by the time point C is reached. Upwardly projected high pressure vapor jets issue from the annular series of ports 83 to drive and maintain the cap 35 up and seated on the underside of the pressure plate 86, as shown in FIG. 4. The vapor flows past the lower edge of the lifted cap and forcibly fills the underside of the cap and the head space of the container to replace the air at these locations, along with sterilizing the surfaces thereof. For the brief interval of container travel between points C and D, vapor injection is continued without any change in the relation of the sealing head to the cap and the container. During this vapor injection phase of the sealing cycle, air is effectively and quite completely purged from the container head space.

At point D, the drum cam, acting on roller 68, starts to move the sealing head down, the entire head descending until the point E is reached, at which point the cap is reseated on the container and traps the vapor therein. This point E may be located a few degrees ahead of taiuer travel between points G and H (FIG. 1).

point P where the roller 39 drops off the end of cam 90 and valve 34 closes to discontinue the vapor flow. The Overlap between cap sealing and vapor shut otf assures a full measure of vapor within the container head space, while the shut off at this time assures vapor economy.

Along with reseating the cap on the container at point E, it will be seen that the pressure plate 8d of the sealing head will apply top pressure to the container to depress it and the support pad 36 so that the pad is forced into frictional driving engagement with the head flange 38 of the rotating, shaft 39. Depression of the pad will occur because the pressure of the spindle bearing spring 74 greatly exceeds that of the pad bearing spring. By virtue of this drive engagement, the pad and the container will be rotated and since the cap, the pressure plate and the spindle are already rotating, the cap and the container will rotate in unison with respect to the threadrolling tools 91.

During the downward movement of the sealing head, as soon as the reactive force on the spindle '71 overcomes the pressure of spring 74, the upper case 64 of the sealing head continues to move down relatively to the spring-biased spindle 71 and the lower portion of the sealing head carried thereby until the cam roller 93 reaches the lowermost level of the drum cam groove 66 located a selected point, as at G, with respect to the valve closing point P. This relative motion first results in imposing through the pressure plate 89 the preset pressure of spring 74 on the cap and the container to force the cap and its sealing gasket into sealing relationship with the mouth rim of the container, thereby hermetically sealing the container. Then it causes the thread roller cams '70 to spread apart the upper ends of the rock levers 96 so as to bring the thread-rolling discs 91 into pressure contact with the deformable skirt of the cap 35 in the region adjacent to the upper end of the thread formation on the container neck by the time point G has been reached. The relative positions which the several parts assume at this time, with the exception of the spinning discs, are shown in FIG. 5. The container and cap are rotating with spindle 71 and support pad 36 so that the thread-rolling discs progressively deform the cap skirt around its entire periphery and downwardly into conformity with the screw thread on the container neck, the discs travelling down along the lower 'side of the container screw thread to the lower position shown in FIG. 5. This completes the container sealing operations.

This thread rolling operation is effected during 0011-. At point H, the sealing head starts up to release the sealed container from the discs 91 and pressure plate 8% and the pad biasing spring lifts the released container and pad to the upper normal stationary position of the pad. The head rises to its uppermost position before the take-out star wheel 11 is reached, this star wheel receiving the sealed container and discharging it onto the line conveyor 4.

It is apparent from the foregoing description of the machine used for the purpose of illustrating the invention that the vacuumizing of threaded containers performed thereby is both simple and automatic and that the method is in no way dependent upon vacuum pumps, complicated cap lifters and extraneous cooling equipment. Instead there is simple cap lifting by vapor pressure and positive vapor entrapment within the container by its cap with positive afiixing of the cap upon the container,

all performed at high speed'in an extremely short time so that maximum vacuum condition is obtained in the sealed containers when the trapped vapor subsequently cools in due course. a

While a condensable vapor, such as steam, is injected into the'container head space to provide a vacuum type seal, it will be apparent that the container head space 3 may be filled with a non-condensable vapor such as a desired inert gas'to provide the usual vapor type seal, or with a mixture of vapor and gas in dependence upon the nature of the container contents, as desired, to assure a long shelf-life therefor, simply by connecting the inlet pipe 5'3 to an appropriate supply source.

Having thus described the invention and many of its advantages, it will be apparent to those skilled in the art that various changes may be adopted without departing from the spirit and scope of the invention as particularly defined in the appended claims.

What is claimed is:

1. In the art of sealing product-filled containers having an external screw thread neck finish, the method which comprises placing a plain-skirt cap loosely on the mouth of a container, subjecting the cap to the lifting force of upwardly and inwardly directed vapor jets directed against the cap skirt to raise the cap relative to the container and admit vapor into the head space of the container for an interval sufficient effectively topurge air therefrom, forcibly pressing the cap down into hermetic sealing relationship with the mouth rim of the container to trap the admitted vapor in said head space while the cap is subjected to said vapor-jet flow, and

progressively deforming the cap skirt around its entire periphery and downwardly into conformity with the screw thread on the container neck while the cap is being forcibly pressed down in said sealing relationship.

2. The method of vacuum-sealing product-filled containers having an external screw thread neck finish which comprises placing a plain-skirt cap loosely on the mouth of a container, lifting said cap with respect to the container by the force of upwardly and inwardly directed jets of hot condensable vapor circumferentially around the region of the lower edge of the cap, maintaining said cap lifted by said vapor jets to admit hot vapor into the head space of the container for an interval sufficient effectively to purge air therefrom, forcibly pressing the cap down into hermetic sealing relationship with the mouth rim of the container to entrap said admitted vapor in said head space while the cap is subjected to said vapor jet flow, and progressively deforming the cap skirt around its entire periphery and downwardly into conformity with the screw thread on the container neck while maintaining the cap forcibly pressed down in said sealing relationship.

3. In a machine for sealing threaded containers having plain-skirt caps loosely applied thereon, the combination of a rotatably mounted container support pad, driving means for frictionally rotating said pad and a loosely capped container supported thereon,

(a) a vertically movable sealing head supported above said pad and movable down to an intermediate position and to a lower position with respect to a container supported on said pad, said head including a rotatably mounted spindle provided with a cap-engaging pressure plate on its lower end for ap plying sealing pressure between said cap and container, in said lower position of said head,

(h) a vapor ejector ring carried by said spindle coaXially of said pressure plate to encircle the upper portion of said container, said ring being spaced below said pressure plate a distance approximately equal to the cap skirt depth, to accommodate cap lifting into engagement with said pressure plate by emitted vapor and admit vapor into the head space of said container in said intermediate position of said head, said pressure plate serving to reseat the cap on the container during head movement from said intermediate position to said lower position and to establish frictional driving engagement between said pad and said driving means,

(e) thread-rolling means carriedby said spindle for progressively forming'thread-like securing conformations in said cap skirt, in said lower position of said head, a yieldable pressure connection between said head and said spindle permitting relative'axial motion therebetween after said cap is reseated on said container, cam means carried by said head for actuating said thread-rolling means into operative contact with said cap skirt responsively to said relative motion, and

(d) actuating means operatively associated with said sealing head for moving it downwardly with respect to said support pad and maintaining it in each of said positions for predetermined time intervals.

4. The sealing machine as defined in claim 3 wherein driving means connected to said spindle is provided for rotating said spindle and its attached pressure plate in unison with the rotation of said support pad and in the rotation direction which causes said thread-rolling means to move and deform said cap skirt downwardly during formation of the thread-like securing conformations in the skirt.

5. The machine as defined in claim 3-, in which is provided a spring closed valve means for controlling vapor flow from said ejector ring, together with cam means for actuating said valve means to open position when said sealing head is downwardly moved to its said intermediate position and to reclose said valve concomitantly with said head movement to said lower position.

6. The machine as claimed in claim 5 in which said vapor ejector ring includes a narrow vertical wall to encircle said container, said wall having two annular series of spaced ports formed therein, one series above the other and inclined inwardly and upwardly at different angles so as to impinge high velocity vapor jets against the periphery and lower edge of the cap to lift the same.

7. In a machine for sealing threaded containers having plain-skirt caps loosely applied thereon, the combination of a rotatably mounted container support pad,

(a) a vertically movable sealing head supported above said pad and including a rotatably mounted spindle provided with a cap-engaging pressure plate on its lower end, a yieldable pressure connection between said head and said spindle,

(b) actuating means operatively connected to said head for moving it down to an intermediate position and to a lower'position with respect to said pad and a con tainer resting thereon, and maintaining said head in each of said positions for predetermined time intervals,

(c) a vapor ejector ring carried by said spindle coaxially of said pressure plate and adapted to encircle the upper portion of said container, said ring being spaced below said pressure plate a distance approximately equal to the cap skirt depth to eifect cap lifting by projected vapor to an extent limited by said pressure plate and admit vapor into the head space of said container in said intermediate position of said head, said plate reseating and pressing the cap into sealing position on the container under the force of said yieldable pressure connection by said head movement to said lower position,

(d) thread-rolling means carried by said spindle for progressively forming thread-like securing conformations in said cap skirt, in said lower position of said head, said head being moved axially relative to said spindle after said plate presses the cap on the container, cam means carried by said head for actuating said thread-rolling means into operative contact with said cap skirt in response to said relative axial movement, and

(c) drive means for effecting relative rotation between said thread-rolling means and said container While the cap is held in said sealing position.

8. In a machine for sealing threaded containers having plain-skirt caps loosely applied thereon, a rotary sealing mechanism comprising a turret and a table therebelow, both rotatably supported, and means to rotate them in unison,

(a) a plurality of container support pads rotatably mounted in uniformly spaced relation in a circle around said table, means to feed containers onto said pads individually at an intake position and means to remove them at a take-out position spaced from said intake position,

(b) vertically movable sealing heads slidably mounted on said turret in alignment with said pads, each of said heads comprising a top case, a vertical spindle rotatably and axially movably mounted in said case and extending downwardly therefrom, a bearing block rotatably fixed on said spindle to move vertically therewith and slidably mounted on said turret to hold said spindle against lateral deflection, spring pres sure means biasing said spindle downwardly in said case and adapted to apply top sealing pressure on a container and its cap, a cap-engaging pressure plate fixed on the lower end of said spindle, thread-rolling means carried by upright rocker arms pivoted on said bearing block disposed laterally of said pressure plate and operable against the skirt of a cap to progressively form thread-like securing conformations therein,

a vapor ejector ring carried by said bearing block coaxially below said pressure plate a distance approximately equal to the cap skirt depth and adapted to encircle the upper portion of a container and its cap to effect vapor jet cap lifting to an extent controlled by said pressure plate, and a spring-closed valve carried by said ring to control vapor flow therefrom,

(c) a drum cam mounted generally concentrically of "said turret and operatively connected to the top case of each of said sealing heads to move each head down to a cap lifting position and to a lower container sealing and cap afiixing position at first and second points spaced from each other in the circular path of travel of said heads, and said points located between said intake and take-out positions,

(d) an arcuate valve operating cam mounted generally concentrically of said turret starting adjacent to said first point and terminating adjacent to said second point in the travel pat-h of said heads for opening the valves of the heads traversing said operating cam,

(e) said downward movement of each head at said second point effecting reseating and sealing of the raised cap on the container under the force of said spring pressure means and relative axial motion between the top case and spindle of the head,

(if) the top case of each of said heads having cam means in operative engagement with said rocker arms and operable in response to said relative axial motion to actuate said thread-rolling means into operative contact with the skirt of the reseated cap to afiix the cap on the container while the cap is held in sealing position :on the container by said spring pressure means,

(g) and drive means for rotating each pad, container and spindle with respect to said thread-rolling means during sealing and affixing the cap on the container.

9. In a machine for sealing threaded containers having plain-skirt caps loosely applied thereon, the combination of a rotary table, a multiplicity of container support pads rotatably and depressibly mounted in equally spaced relation in a circle around said table to which successive containers are delivered at an intake position and removed at a take-out position angularly spaced from the intake position,

(a) a sun gear under said table, a stub-shaft having a head flange underlying and spaced from each of said pads, a gear on each shaft in mesh with a planet gear rotatably mounted on said table and in mesh with said sun gear, to rotate said shafts as said table is rotated, and to rotate said pads and the containers thereon when depressed,

(b) a rotary turret above said table and connected thereto for unitary rotation therewith, vertically movable sealing heads slidably mounted on said turret in alignment with said pads, a downwardly extending spindle rotatably and slidably supported in each of said heads, spring pressure means biasing each spindle downwardly in its head, a second sun gear and a drum cam fixedly mounted generally concentrically of said turret and encircled by said sealing heads, a gear on each of said spindles in mesh with a planet gear rotatably mounted on said turret and in mesh with said second sun gear, whereby said spindles are rotated in unison with rotation of said stub shafts, cam follower means connecting each of said heads to said drum cam, whereby said cam controls the vertical position of said heads, moving each head down to a cap lifting position and to, a lower container sealing and cap affixing position at first and second points spaced from each other in the circular travel path of said heads and said points located between said intake and take out positions,

() a cap-engaging pressure plate secured to the lower end of each of said spindles, a vapor ejector ring nonrotatably supported by each of said spindles below said pressure plate a distance approximately equal to the cap skirt depth and adapted to encircle the upper portion of a container and in said cap lifting position to direct streams of vapor about the container and its cap to lift the cap an extent controlled by said pressure plate and admit vapor into the head space of the container, a spring-closed valve carried by each of said ejector rings to control vapor flow therefrom,

(d) an arcuate valve operating cam mounted generally concentrically of said turret starting adjacent to said first point and terminating adjacent to said second point in the travel path of said heads for opening the valves of the sealing heads traversing said operating cam,

) said downward movement of each head at said second point being through a distance greater than the distance between said pressure plate and said ejector ring and effecting reseating and sealing of the raised cap on the container under the force of said pressure means, depression of the container and the pad on which 'it rests so that the container and its cap are rotated, and relative axial motion between the sealing head and its spindle, 1

) thread-rolling means carried by the spindle of each of said heads laterally of said pressure plate and operable against the skirt of a reseated cap to progressively form thread-like securing conformations in the cap skirt, and cam means on each of said heads for actuating said thread-rolling means thereof into operative contact with the skirt of the reseated cap in response to said relative axial motion between said head and its spindle at said sealing position to afiix the cap on the container before said take-out position is reached.

' 10. The machine as defined in claim 9 wherein each of said pads is disposed in a cavity under a wear plate which is on top of the table and covers the cavity, said plate having an opening therethrough coaxially of the cavity, a central protuberance on said pad equal to the thickness of said plate and disposed in said plate opening, anda spring biased bearing carried by said stub shaft in contact with the underside of said pad at the center thereof, said hearing normally yielding holding said pad out of contact with the head flange of said stub shaft aand in frictional holding engagement with the underside of said wear plate, whereby the container supported on the pad is'held against rotation about its axis until top sealing pressure is applied thereto at said second point.

11. The sealing machine as claimed in claim 9, in which said turret is formed with vertical slideways of outwardly open V-shape in its periphery for the reception of said sealing heads therein on a common center line circle, keeper bars retaining said heads in said slideways, one keeper bar in the space between and in engagement with each two adjacent sealing heads, each head being formed with V-sides complemental to the sides of said slideways, one half of the center-to-center distance between said heads along said center line being less than the container diameter, whereby an increased number of, said heads. are

' accommodated on said turret without increasing the diameter thereof, and the sides of contiguous ejector rings of said heads being substantially straight and generally radial of the center of said turret for lateral clearance between them. i

References Cited by the Examiner UNITED STATES PATENTS 2,337,170 12/43 Wareham 53-109 X 2,352,761 7/44. Bell 53-109 3,013,371 12/61 Gamble 53-329 3,098,334 7/63 Barnby et al 5342 FRANK E. BAILEY, Primary Examiner.

TRAVIS S. MCGEHEE, Examiner. 

1. IN THE ART OF SEALING PRODUCT-FILLED CONTAINERS HAVING AN EXTERNAL SCREW THREAD NECK FINISH, THE METHOD WHICH COMPRISES PLACING A PLAIN-SKIRT CAP LOOSELY ON THE MOUTH OF A CONTAINER, SUBJECTING THE CAP TO THE LIFTING FORCE OF UPWARDLY AND INWARDLY DIRECTED VAPOR JETS DIRECTED AGAINST THE CAP SKIRT TO RAISE THE CAP RELATIVE TO THE CONTAINER AND ADMIT VAPOR INTO THE HEAD SPACE OF THE CONTAINER FOR AN INTERVAL SUFFICIENT EFFECTIVELY TO PURGE AIR THEREFROM, FORCIBLY PRESSING THE CAP DOWN INTO HERMETIC SEALING RELATIONSHIP WITH THE MOUTH RIM OF THE CONTAINER TO TRAP THE ADMITTED VAPOR IN SAID HEAD SPACEWHILE THE CAP IS SUBJECTED TO SAID VAPOR JET FLOW, AND PROGRESSIVELY DEFORMING THE CAP SKIRT AROUND ITS ENTIRE PERIPHERY AND DOWNWARDLY INTO CONFORMITY WITH THE 